Chuck Connors and Johnny Crawford in “The Rifleman” on
ABC TV from September 30, 1958 to April 8, 1963. 

John Ernest Crawford (March 26, 1946 – April 29, 2021)

Johnny Crawford was an actor, singer, and musician. He first
performed before a national audience as a Mouseketeer. At age
12, Crawford rose to prominence playing Mark McCain in the
ABC Western series The Rifleman, which he was nominated for
an Emmy Award for Best Supporting Actor at age 13 for his
work om the show.

Crawford had been diagnosed with Alzheimer’s disease in 2019.